01/02/2010: Backward and forward, this date is lining up as a rarity

A lot of folks woke up on New Year's Day unsure of whether they were coming or going.

For those who watch the calendar, Saturday could be equally discombobulating.

The date 01/02/2010 is a palindrome: A rare confluence of month, date and year that reads the same backward as forward.

The last palindrome date was Oct. 2, 2001. But before that, more than six centuries passed since the numerals last aligned on Aug. 31, 1380.

"They are very rare," said Aziz Inan, a numbers-obsessed professor of electrical engineering at the University of Portland.

The 21st century will bring a scant 12 palindrome dates, said Inan.

While fascinating to a few, palindrome dates aren't likely to inspire a stampede to the altar as did the "lucky" date 7/7/07.

In China, where 9 is more auspicious, record numbers wed on 9/9/09.

"Palindromes don't really mean anything," Inan conceded.

But to someone who loves numbers, they're just so ... lovable.

"Numbers are like people," Inan said. "Each one has its own character, its own uniqueness."

Don't get him started on the number 48. (Square each digit to get 16 and 64. Subtract 16 from 64 to get, drumroll, 48!) On a recent bus trip, Inan informed the driver that the number of his coach — 1706 — is the year Benjamin Franklin was born.

The voluble professor has made it his mission to spread the word about numerical oddities of all sorts. He made custom T-shirts to commemorate Jan. 2, 2010, the century's second palindrome date. In his spare time, he's writing a book of math puzzles.

Inan was pondering symmetrical numbers — 1991, 220022 — when it occurred to him that some dates must fall into the category. He quickly discovered he wasn't the first to hit on the notion.

But being an academic, he decided to write what he believes to be one of the first papers about palindromic dates.

It's not exactly groundbreaking research, but Inan was able to find a forum: "Pi in the Sky," a magazine for high-school math teachers and students, which will publish his article next year.

Sussing out palindromic dates doesn't require any lengthy calculations. Just an understanding of the nature of the calendar and some basic rules.

For example, in countries like the U.S., where dates are designated as "month, day, year," any palindromic date in the 21st century will have to occur on the second day of the month, said Matthew Conroy, senior lecturer in mathematics at the University of Washington. That's because the first two digits of the year will always be "20." Flip them around to form a mirror image of the day, and you always get "02."

The same rule explains why there were no palindromic dates between the 1400s and 1999.

Flip the first two digits of those centuries and you get 41, 51, 61, 71, 81 and 91. But there can be no more than 31 days in a month. For the same reason, there will be no palindrome dates between the 24th and 30th centuries.

Countries that designate dates by listing the day first and month second will have 29 palindrome dates this century, all in the month of February, Inan said.

And both calendar systems will share two palindrome dates this millenium: 02/02/2020 and 12/12/2121.

"The entire world will celebrate," Inan said, pausing to add: "Obviously, I am dreaming."

Words and entire sentences can also be palindromes: dad; kayak; rats live on no evil star.

Many people believe they see hidden significance and secret codes in patterns of numbers and letters: Think "DaVinci Code," or 666, the supposed "mark of the beast." But both Inan and Conroy caution against reading too much into these things.

Coincidences and chance patterns pop up much more frequently than people realize, Conroy said. "Some things seem so strange, you would imagine they have significance when they really don't."

But even the Turkish-born Inan admits to occasionally experiencing moments when you could cue the spooky music. Like when he split and factored U.S. Independence Day (07/04/1776) to get: "704=4x4x44 and "1776=4x444."

"I said: My god. Maybe the founding fathers chose this special day. Of course, I don't really think that is the case," he said with a laugh, "But it made me wonder."

Sandi Doughton: 206-464-2491 or sdoughton@seattletimes.com